Pivot Multiple Fields With Dynamic Descriptions - sql

Question

I'm trying to pivot the following and I don't know why I'm having such a hard time figuring it out.
Data Script
create table #data (ID varchar(50)
, nm varchar(50)
, val decimal(18,2)
)
insert into #data values (1,'Name1', 100.00),
(1,'Name2', 200.00),
(2,'Name3', 300.00),
(2,'Name4', 400.00),
(2,'Name5', 500.00),
(3,'Name6', 600.00),
(4,'Name7', 700.00),
(4,'Name8', 800.00),
(5,'Name9', 900.00)
Wanted Results As A Table in SQL Server
1 Name1 100 Name2 200
2 Name3 300 Name4 400 Name5 500
3 Name6 600
4 Name7 700 Name8 800
5 Name9 900
Update:
The following provides results in two fields, but what I really want is for the Name and Values to all exist in separate columns, not in one,
SELECT id,
(
SELECT nm,val
FROM #data
WHERE id = d.id
ORDER BY id FOR XML PATH('')
)
FROM #data d
WHERE
id IS NOT NULL
GROUP BY id;

Answer 1

This is an example of "pivot" not aggregate string concatenation. One issue with SQL queries is that you need to specify the exact columns being returned. So, this cannot be dynamic with respect to the returning columns.
The following returns up to three values per nm:
select id,
max(case when seqnum = 1 then nm end) as nm_1,
max(case when seqnum = 1 then val end) as val_1,
max(case when seqnum = 2 then nm end) as nm_2,
max(case when seqnum = 2 then val end) as val_2,
max(case when seqnum = 3 then nm end) as nm_3,
max(case when seqnum = 3 then val end) as val_3
from (select d.*,
row_number() over (partition by id order by (select null)) as seqnum
from #data d
) d
group by id;
Note that you probably want the columns in insertion order. If so, you need to specify a column with the ordering. I would recommend defining the table as:
create table #data (
dataId int identity(1, 1,) primary key,
ID varchar(50),
nm varchar(50),
val decimal(18,2)
);